Two-piece solid golf ball

• US 4,141,559 A
• Filed: 12/27/1976
• Issued: 02/27/1979
• Est. Priority Date: 12/27/1976
• Status: Expired due to Term

• Current Assignee: Uniroyal Chemical Company Inc (Lanxess AG)
• Original Assignee: Uniroyal, Inc. (Compagnie Generale DES Etablissements Michelin SCA)
• Inventors: Melvin, Terence, Pieroni, Joseph K., Martin, Frank S., Little, James F.
• Primary Examiner(s): Marlo, George J.
• Application Number:
  US05/754,715
• Time in Patent Office: 792 Days
• Field of Search: 273/235 R, 273/232, 273/218, 273/235 A, 273/235 B, 273/220, 273/230, 273/62
• US Class Current: 473/372
• CPC Class Codes: A63B 37/0003 Golf balls
• CPC Class Codes: A63B 37/0004 Surface depressions or protrusions
• CPC Class Codes: A63B 37/0006 Arrangement or layout of dimples
• CPC Class Codes: A63B 37/0018 Specified number of dimples
• CPC Class Codes: A63B 37/0019 Specified dimple depth
• CPC Class Codes: A63B 37/002 Specified dimple diameter
• CPC Class Codes: A63B 37/0021 Occupation ratio, i.e. percentage surface occupied by dimples
• CPC Class Codes: A63B 37/0033 Thickness
• CPC Class Codes: A63B 37/0064 Diameter
• CPC Class Codes: A63B 37/0065 Deflection or compression
• CPC Class Codes: A63B 37/0074 Two piece balls, i.e. cover and core
• CPC Class Codes: A63B 37/008 Diameter
• CPC Class Codes: A63B 37/0083 Weight; Mass
• CPC Class Codes: B29D 99/0042 Producing plain balls hollow balls B29D22/04
• CPC Class Codes: B29K 2009/00 Use of rubber derived from conjugated dienes, as moulding material
• CPC Class Codes: B29K 2033/00 Use of polymers of unsaturated acids or derivatives thereof as moulding material B29K2035/00 takes precedence
• CPC Class Codes: B29L 2031/54 Balls

Abstract

A two-piece molded golf ball comprised of a resilient core (polybutadiene-basic zinc methacrylate covulcanizate) and an ionomer resin cover, the cover having a dimple design of icosahedral array. This ball has superior flight performance compared to conventional two-piece molded balls.

Claims

1. A solid two-piece molded golf ball having a spherical core having a diameter of 1.505 inches, a PGA compression of 65, a rebound of at least 75% and a specific gravity of 1.20, the said core comprising a cross-linked composition containing 100 parts by weight of polybutadiene elastomer having a cis-1,4-polybutadiene content of 50% by weight or more and from 10 to 60 parts by weight of preformed zinc oxide-methacrylic acid reaction product in which the zinc oxide and methacrylic acid are combined in the proportions required by basic zinc methacrylate, said preformed reaction product being finely ground to a fineness such that at least 99% passes a 325 mesh sieve, said core composition containing a free radical generating curing agent in amount sufficient to cure the composition, the said core being surrounded by a cover composition of sufficient thickness to provide a ball diameter of 1.680 inches, said cover composition comprising an ionomer resin which is a thermoplastic, resinous ionic copolymer of an olefin having from 2 to 8 carbon atoms and a metal salt of an unsaturated monocarboxylic acid containing from 2 to 8 carbon atoms, the outer surface of the said cover being painted and having a dimple pattern consisting of essentially 252 dimples circular in cross-section, the dimensions of the dimples expressed as mold dimensions being 0.160 inch in diameter by 0.0145 inch deep, said dimples being arranged in an icosohedral array uniformly distributed on the surface of the ball and covering approximately fifty percent of the area of the ball surface, the molded ball having been deflashed by centerless grinding, whereby the ball exhibits improved flight characteristics.